UILable实现按照文字多少定义大小

下面文章转载自http://wangjun.easymorse.com/?m=201106

UILable显示文字，大多数情况下文字是动态的，所以UILable的大小需要自适用,下面是实现的具体代码：

myLable=[[UILabel alloc] initWithFrame:CGRectMake(0, 23, 175, 33)];

[myLable setFont:[UIFont fontWithName:@"Helvetica" size:10.0]];

[myLable setNumberOfLines:0];

[myLable setBackgroundColor:[UIColor clearColor]];

[myAdView addSubview:myLable];

UIFont *font = [UIFont fontWithName:@"Helvetica" size:10.0];

CGSize size = [text sizeWithFont:font constrainedToSize:CGSizeMake(175.0f, 2000.0f) lineBreakMode:UILineBreakModeWordWrap];

CGRect rect=myLable.frame;

rect.size=size;

[myLable setFrame:rect];

[myLable setText:text];